Trek’s first-time full-susser for the little ripper

Product Overview

Trek Fuel Ex Jr


  • Tons of standover clearance; quality suspension components; plenty of stopping power; wide gearing range; proper mountain bike tyres.


  • Heavy; needs a shorter stem; brake levers lack reach adjustment for smaller hands.


Trek Fuel Ex Jr (2016) review


Price as reviewed:


Need to know:

  • Kids’ full- suspension bike with 26in wheels and 2x drivetrain
  • 90mm of travel front and rear
  • Powerful Shimano M355 disc brakes
  • Comes with all the standard Fuel EX features, including ABP pivot, Full Floater suspension and Evo Link

The Trek Fuel EX Jr is literally a children’s version of the regular Fuel EX, albeit with smaller 26in wheels and 90mm travel front and rear. It’s only available in size small (15in), and depending on rider height, it should fit kids aged between eight and 12 years old. Any older, or taller, and they can upsize to the regular adult range.

Trek Fuel EX jr riding

After a string of hardtails, this is my daughter Alice’s first full-suspension bike, and she seemed to settle into it straight away. I took time setting up the suspension as she’s so light. She ended up running less than 50psi at both ends — you need a low-pressure shock pump to set this accurately. I also swapped the stem for a 35mm because the bike comes as standard with a 70mm, which is too long even for most adults.

Watch our first look at the Trek Procaliber hardtail

You always keep an eye on your kids when riding off-road, but the first thing I noticed was that Alice was glued to my wheel on the singletrack. She was riding with a lot more confidence and looked much more stable on the bigger wheels — her previous bike had 24in wheels, and while they rolled along OK, they seemed to get hooked more easily on the trail. She also had disc brakes, something not seen on entry-level kids’ bikes.

The Shimano brakes have lots of modulation, so no danger of going over the bars, but unfortunately the lever is still an adult size, so it was impossible to get the levers close enough to the bar. As such, Alice couldn’t brake and grip the bar at the same time.

Trek Feul Ex jr shock_edited-1

X-Fusion shock gives 90mm travel

Another issue with the Fuel EX Jr is the weight. It’s 13.6kg (30lb) with pedals, which is heavy for a 90mm-travel kids’ bike. The full-sized Giant Anthem we tested last month weighed 2lb less. To save weight I’d definitely consider converting the tyres to tubeless and fit a 1x drivetrain.

You could argue that a kid needs smaller gears than an adult, but most don’t have the skill or power to scale really steep technical climbs where gears are essential.

All I can say is, Alice never once shifted into the bigger 32t chainring during the whole time on the bike, as the action of the shifter was too heavy for her little hands to operate.

As a parent, one of the big issues about buying kids’ bikes is that they grow out of them too quickly. So, £1,400 is a huge amount when you may only get six months’ use, although you may claw quite a bit of that back on resale.

Alice thinks the Fuel EX Jr is a great bike and it has definitely improved her riding and boosted her confidence. It also means she’s still keen to go riding with dad, and in that respect it’s money well spent.

Trek Fuel Ex Jr packshot


Frame:Alpha Platinum aluminium
Shock:X-Fusion Microlite RL, 90mm travel
Fork:X-Fusion Velvet RL, 90mm travel
Wheels:Formula hubs, Bontrager AT-650 rims, Bontrager XR2 26x2.2in tyres
Drivetrain:Alloy chainset 32/24t rings, Shimano Deore shifters, f-mech and r-mech
Brakes:Shimano Altus M355, 160mm
Components:Bontrager Elite bar, Bontrager alloy stem, Bontrager SSR seatpost and Dialled 24in saddle
Weight:13.61kg (30lb)
Size ridden:S
Rider height:4ft 9in
Head angle:69.2°
Seat angle:72°
BB height:335mm
Front centre:625mm
Down tube:605mm
Top tube:605mm
Top tube:535mm